$J$ $K$ $L$ If: $ JL = 17$, $ KL = 3x + 5$, and $ JK = 6x + 3$, Find $KL$.
Solution: From the diagram, we can see that the total length of ${JL}$ is the sum of ${JK}$ and ${KL}$ $ {JK} + {KL} = {JL}$ Substitute in the expressions that were given for each length: $ {6x + 3} + {3x + 5} = {17}$ Combine like terms: $ 9x + 8 = {17}$ Subtract $8$ from both sides: $ 9x = 9$ Divide both sides by $9$ to find $x$ $ x = 1$ Substitute $1$ for $x$ in the expression that was given for $KL$ $ KL = 3({1}) + 5$ Simplify: $ {KL = 3 + 5}$ Simplify to find ${KL}$ : $ {KL = 8}$